Mast arm



Aug. l14, 192s.

J. J. sHicKLUNA MAST ARM Filed N0v. 24, 1923 s sne'ets-sneet 1 Aug. 14, 192s.'

J. J. sHlcKLuNA MAST ARM Filed Nov. 24, 19

2% 5 Sheets-Sheet Tiwy?? Aug. 14, 1928. 1,680,573

V J. J. SHICKLUNA MAST ARM Filed Nov. 24', 1923 3 Sheets-Sheet 3 I ggg JT J Oberoi.

Patented Aug. 14, 19278.

'unirse stares JOSEPH J. SVHICKLUNA, OF BUFFALO, NEW YORK.

Application led November 24, 1923. Serial No. 676,723.

My `invention relates to an improved mast arm for supporting electric lights. v

One of the primary objects of my in ventionvis the provision of a mast arm of this type which is collapsible so that it will occupy comparatively little space when storing or shipping the same in quantities.

Another object of my invention is to pro- `vide a mast arm in which the arm proper may be braced from the bottom or supported from a higher point than Vits point of lconnection to the mast, or so that it may be both brac-ed from the bottom and supported from a higher point.

Another object is to provide an improved i overhead support for the mast arm and 'to provide a mast arm which is formed of slender members comprising the arm proper, a brace, and a truss or truss structure connecting the arm proper with the brace, all of which may be used with or without said overhead support.

A still further object isl to provide a mastarm with a reversible brace and to connect both the inner end of the arm proper and the inner end of the brace to the mast or pole in an improved and simplified manner.

A still further Objectis to provide an insulation arm for the mast arm which can be positioned either above or beneath the mast arm, and which has angular or oblique end portions, preferably directed laterally and upwardly; said insulation arm being, however, reversible, and when reversed having the angular or oblique end portions directed laterally and downwardly; andrto otherwise improve on mast arms of this type.

lVith the above and other objects in view, the invention consists in the novel features `of construction and in the arrangement and combination of parts to be hereinafter described and m-ore particularly pointed out in the subjoined claims. t

In the drawings 1 1 Fig. 1 is a side elevation of the upper portion of amast or pole having my improved mast arm connected thereto.

Fig. 2 is a horizontal section taken on line 2 2, Fig. 1, the overhead support or guy wire being omitted. 'e

Fig. 3 is a transverse section taken on line 3 3, Fig.- 1, looking in the direction of the arrow crossing said line.

of overheadvsupport or guy wire is secured ,i

to the mast; said view showing also the` manner of connecting said support or wire to said fitting. 1

Fig. l0 is a, detached perspective, view of one of the mastl arm fasteners adapted to be driven into the. mast or pole and secured thereto. Y l

Fig. 11 is a horizontal section taken on lille 2.

Fig. 12is an enlarged transverse section taken on line 12 12, Fig. -,1, loolringin the direction of the arrow crossing said line.

Fig. 13 is an enlarged horizontal section taken on line 13 13, Fig. l.

F ig. 14 is a side elevation of the outer end of the mast arm showingthe insulator arm secured to the upper side thereof.

Fig. 15 is a similar view showing the insu lator arm secured to mast arm.

Fig.v16 is a section similar to Fig. 6, showing the brace reversed.

Fig. 17 is an enlarged transverse section taken on line 17-17, Fig. 15. Y

Fig. 18 is an enlarged transverse vsection taken on line 18 18, Fig. 15, looking 4in the direction of the arrow crossing said line.

Mast arms of thetype to which this in'- vention relates are usually fastened to masts or otheruprights arranged at the side of a road-or highway, and are adapted to eX- tend outwardly a suitable distance from such mast or upright with sufficient rigidity to withstand storms and be properly' secured` to thesupport so thatvthey cannot become loosened; the' object being to suspend an electric lamp from the'outer end. thereof with aview of lighting the road or highway over the greatest pssiblearea,

Mast arms as now, Constructed require the. under side of the large storage facilities at the place of manuform, asv provided for in my invention, the

various parts thereof can be disassembled and conveniently stored in a small space, and these parts can be boxed .in large quantities so that when shipped they occupy comparatively little space. p Y

Under the principle involved in this invention, I have-illustrated a representative form, or what I now consider the preferred construction, of mast armfalling Within the scope of my invention;

Referring to the drawings in detail, the reference numeral 20 designates a mast pole, or other upright, which is usually constructed of wood and set at the side of a road, and 2l is my improved mast arm considered as a whole and including' its brace y or other support Vand `necessary adyuncts. VThis mast ai'm comprises the mast arm proper, or what maybe termed the reach 22,

which is formed of a head or Ycasting 23v and inwardly-divergingbars 24, preferably of channel formation in cross section. The outer endsl of these bars 'are fastened into said head or casting in any suitable manner, but preferably as will be hereinafter described, while the inner ends thereof are fastened to the upright at opposite sides thereof, preferably by inserting them into substan-` tially channel-shaped fasteners 25 and constructed as best shown in Fig. 10.

Each of said fasteners 25 comprises an inner wall or web 26 and flanges 27, which give to said fastener the channel shape transversely, and at its inner end each fastener has an end wall 28. Each fastener is therefore open at its outer end and at one side.

The bars 24 are adapted to be inserted between'the flanges 27 of the fasteners through` the open 'outer ends thereof, the inner ends of said bars bearing against the end walls 28. At the outer edges of the flanges 27 andend wall 28 of eaclivfastener, retainer prongs 29 are provided which are bent at right angles to said walls and prevent displacement of the bar24 inserted into the fastener.

The fasteners are made of suitable material, preferably malleable iron, and the re-l tainer prongs 29 maybe hammered firmly against the bars when inserted into the fasteners. At the inner side of the fasteners the latter, and driven through the registering bolt holes and into the mast are lag bolts 32, or other suitable fastening devices. By employing inwardly-diverging b ars, such as 24 or the like, the niast arm is given certain laterally bracing qualities.

The head or casting-23 is elongated and the inner end thereof is channeled at the bottom, as at 33, the side walls of the channel structure so provided diverging inwardly, as best shown in Fig. 13, to conform to the trend of the bars 24. At their lower edges, the side walls of this channel formation are connected by a narrow cross bar 34 and the outer ends of the reach bars 24 are inserted into this channel formation, the upper faces thereof bearing against the top wall of such channel formation while thel lower faces of said bars vlie in ycontact with said cross bar 34. Near the outer end of this channel formation, or pocket portion as it may be termed, the side walls are provided with alined openings 35, and near the outer ends of the reach bars 24, openings 36 are provided which register with the openings 35, and throughall of these openings a retainer pin 37 is inserted, thus preventing Withdrawal of the reach bars from said pocket portion.

Depending from the lower ledges of the side .walls of said pocket portion are lugs 38, for a purpose to appear hereinafter. The head or casting 23 terminates at its outer end in a depending socket 39 which opens downwardly and is internally threaded to receive a connector nipple 40 onto which an electric lamp fitting' (not shown) may be secured; said nipple receiving the lamp fitting in the event that the latter has an intei'nal thread. However, when the lamp fitting has an eXtei-nalthread, the nipple 40 is dispensed with and the threaded portion Vof thel fitting is threaded directly into the socket 39. y Y

' The head or casting-23 is of T-forination yin cross section between the socket 39 and the l pocket or channeledrportion 33, shown at 4l; the web of said T-formation being enlarged laterally at oppositeA sides, as at 42, to form a vertical boss. Through this head, (1o-axial with said boss, is a bolt hole 43 through which an insulator arm 44 arranged transversely with respect to said head, abolt 45 is passed, said bolt having a nut 46 threaded thereon to retain the insulator arm in position.

Specifically describing said insulator arm and its connection to said head or casting, itvwill be noted that it has a central horizontal portion 47 and oblique end portions 48, and the outerrends thereof ai'e made cylindrical and provided with external screw threads, glass or other insulators 49, which are internally threaded, being applied thereto. This insulator army, in the main, is of T-forination4 in crosssection, and midway between lits 'ends the web thereof is enlarged toV form a cent-ral boss through which a bolt hole 5l is axially formed. 1

At the top ofthe head or cast-ing 23, a pair of alined tongues 52 areprovided which extend in thev direction of the length of saidvr head or casting adjacent the bolt .hole 43 therein, while at the bot-tom of said head or casting a 'similar pair of alined tongues 53 are provided.

At one edge of the insulator arm, transverse grooves 54 are .cutor `otherwise formed, said grooves being in a plane bisecting the bolt hole 5l in said arm, similar grooves 55 are cuter otherwise formed in the opposite edge of said arin, said grooves also being disposed in a plane bisecting the bolt hole 5l. i v e In preferred arrangement, the insulator arm is disposed atthe top of the head or casting 23, as shown in Figs. l, 2, and l2,

and when so arranged the tongues 52 at the top of said head or casting are entered in the grooves 54 of the insulator arni, and when the bolt 45 is fastened in place, said insulator arm is iirrnly counted on said head or casting. By reason ofthe tongue and `groove connection between said head or casting and said arm, rotation of said arm is prevented. A i

To further guard against rotation' of said insulator arm on the `head or casting and to prevent rotation of the boltwithin said head or casting and said insulator arm, a lock washer 5G is employed at the` headed end of said bolt, said washer having tenons 57 formed on4 one side thereof which enter the grooves 55 in the insulator arm, and at the other "side, said washer isfprovided with spaced flanges 58 between which the head of the bolt 45 "is positioned. In this inanner the washer is held against rotation onl the insulator arin andthe bolt against rotation withinth'ewasher. A washer 59 is slipped over the threaded' 'end of said bolt 45, and this washer has grooves 60 formedV therein which receivethe tenons 53 at the bottom of the head orcasting 23, the 'nut46 of the bolt being threaded firmly against said washer 50.' In a sense, this washer 59 also serves as a lock washerfsince rot-ation of the same is prevented by reason'- of itsV tenen and groove connection with the head or casting 23 and a fixed position of said washer will, in a measure, serve as a check against the unthreading of the nut 46 from- V the bolt 45. 1

When the insulator varm is disposed at the top of the head or casting 23, the outer portions of said arms are preferably directed upwardly, as shown inFig.` 12, but this arm,l even though disposed on the top of thehead or casting, maybe reversed. IneitherV case, however, a tongue andgroove connee# rlater arm and the head or casting,'and also between the washer 56 and said insulator arm. In some instances it may be found desirable toposition the insulator arm under.- neath thehead or casting, and when so positionedya tongue and groove connection will be maintained between the head or casting and said insulator arm, and also between the insulator arm and the washer 56, which latter,- in this instance, will be at the bottom instead of at the top, as clearly show-n in Fig. 17, while the washer 59 will be at the top; 'e f Y By providing the'head or casting with the tenons at the top and bottom and providing the insulator arm with grooves at both edges, said insulator arm may be disposed in an upright position atthe top of the head or casting, or at lthe bottom thereof, or it may be disposed in a reversed or depend ing position, eitherat the top or bottoni ,of the heador casting. In some places where installed, authorities may, for appearance sake, choose'any one of the four positions described with reference to the insulator arm; but aside from appearance it will be understood that theV lead wiresare directed y the depending lamp. vIn eases .where theV lamp is hung low from the mast arni, it may be'found `more practical to so place the in "sulator arm that the insulators 49 are in a low position, making it unnecessary to use long lengths of wire from the insulators to the lamp; and in some cases, even where the lamp is hung comparatively high and close to the inast arm, it may be desirable to dis-` pose the insulator'arm in a depending 'position underneath the head or casting 23, as shown in Fig. l5, as the wires leading from the insulators to the lamp will `be comparatively short, and when coiled will enable the lamp to sway without straining the wires connected thereto ;V and at the same timethe complete device will be given a neat appear- Inother instances it may be found desirable to position tlieinsulator arm closer to the inast 20, and for this reason the top wall ofthe pocket or channel portion 3,3 has a bolt hole in its top wall, and on the upper side of said wall a pair of alined tongues 6l are" formed, said tongues being in a plane bisecting said bolt hole and at opposite. sides Y iio rearwardly and passed through the insulator arm from the top, with the lock washer 56 resting on said arm and locking thereinto while lock-ing the head of said bolt against rotation. This bolt passes downwardly through the pocket or channel portiony of the casting and between the two reach bars 24, asA lclearly shown in Fig. A13, and the Awasher 59 is placed @nto said bolt and bears against the under sidesl of said reach bars while the nut 46 is threadedonto the projecting end ofsaid bolt. In this manner the insulator arin may be securelyV fastened at the rear end of' the head or casting and be held againstY rotation in substantiallythe saine 'manner as when secured in one of its forward positions.V

lAlthough I employ the washer 59 at this pointand said washer has the grooves 60 therein, there are no co-acting parts for saidgrooves when the insulator arm is applied to the inner end of the head or casting 23, and said washer is therefore used in the same manner as an ordinary ungrooved washer. Consequently, an ordinary bolt and nut may be used, with a groovcd washer 4such as 59; and in such casesthe grooves of the washer 59 receive the tenons 61.

In Fig. I have shown an ordinary bolt passed through the channeled portion of the head or casting, which bolt maybeused for c fastening the insulator arrn in position; and

inv such cases, thc bolt will be retained in the bolt hole 43, ready for use when it is de*- sired to shift said arm to one of its forward positions.

In connection with the mast arm or, vas' liereinbefore referred to, the reach Aof the mast arm, Iy employ a brace 62 or an over head support 62a.' If desired, both the brace and the overhead support may be used together, but this will, in most instances, not be found necessary and one or the other will suffice. l l

The brace 62 is formed of a T-shapedl bar having a connector fitting 63 at itsouter end y and a securing fitting 64 at its inner end.

The connector fit-ting 63 is a casting having a transverse bolt hole 65 therethrough and 1 it is of a width to fit between the lugs 38 de-l pending `from the head or-casting 23. A bolt 66y is assed through said lugs and through the bolt hole in said rconnector fitting and receives a nut 67Y whereby the outer end of the brace is securely but detachably fastened to the headY or casting V23. This connectorvfitting is slotted, as at 68, and rcceives the web 69 of said T-shaped brace bar. 'Said connector fitting 64 is also provided with a depression 70 along its upper face,

and in this depression are fitted the flanges 71 of the T-shaped brace bar. Rivets 72 are passed through this fitting and through the web of the brace barand serve to rigidly connect said fitting to said bar.

The securing. fitting65 is slotted and formed along a portion ofits length similar tothe connector fitting 64 and fitted onto the inner endfof the brace bar in the same manner as the connector fitting; said securing fitting being fastened to the inner Vend of said brace bar by means of rivets 73. The inner end of this securing fitting is widened transversely to form lateral eXtensions 74, which are of spool-shape, and which are adapted to bear against the mast 20 or tc be partly driven into the same, each spoelv having a bolt hole 75 therethrough, through which lag bolts 76 are passed that are threaded into said mast.' In this manner the inner end of said brace bar is securely fastened to the mast, while the front end thereof isl pivotally connected tothe head or casting 23 of the reach, or mast arm proper.`

lrods 79, 80 converge downwardly. The rod 78 has castings or connector fittings81at opposite ends, which may alsofbe referred to as enlargements, each ofwhich is provided with an outer flat bearing/face 82 and an upwardv and outward extension 83 through which a bolt hole 84 is formed. Each of the rods 79, 80 has a casting, connector fitting, or kenlargement'85 at its upper end, and each of these fittings is provided with an angular seat 86 and with an upward and outward extension 87 through which a bolt hole 88 is formed. The reach bars 24'fit against the angular-seats 86 of the two fittings 85,1while the fiat bearing faces on the fittings 81 bear against the edges of the inwardly-directed flanges of said bareach of the two fittings 81 of the transverse rod 78 co-operating with a fitting at the upper endo'f one of the rods 79 or 8O,Y and such co-operating fittings practically embrace the bars 24. i v

The bolt holes 83 and 88 in co-operating fittings are alined and trend downwardly and outwardly, and passed through these bolt holes are bolts 89 by means of whichk the bars 24 are securely clamped between the outer `ends-of the transverse rod 78 and the vupper ends ofthe rods 79 and 80,a nut 90y being fastened to each bolt 89, as best shown of the flanges ofthe T-shaped brace bar is positionof `said bar shown in Fig. 6; there-v fore, the web of said bar extends downwardly. Vhen, however, this bar is reversed, the web thereoffwill extend upwardly, as shown in Fig. 16, and with dotted lines at 95, Fig. 6. lVhen the brace bar is arranged with its web extending downwardly, a bolt 96 is passed through the upper pair of boltholes 93 in the fittings 91 and a. nut`97 applied thereto to draw these ttings firmly against the edoes of the opposite flanges of said T-shaped ar. When, however, said brace bar isreversed, as shown in Fig. 16, the web thereof would prevent the bolt 96 being passed through the upper pair of bolt holes 93 in said fittings 91. Consequently, the bolt 96 will be passed through the lower pair of bolt holes 94 of said fitting. ln `either case the brace bar will be firmly clamped between the lower ends of the rods 79, by said bolt 96, and flexing of said bar will be prevented by reason of its flanges being held between two pairs .of lugs 92 formed on the inner facesof the fittings 91. It will be clear therefore that the'rods 78, 79, 80, which may be termed truss members, are detachably connected together and serve, at each of the three corners of the triangular truss so formed, to clamp the three main members of the braced mast arm between adjacent ends of such truss members. In this manner the three main members of said braced mast arm are rigidly tied together.

By the construction thus far set forth, a rigid and durable, yet exceedingly light, mast arm is provided, and when it is desired to disassemble the parts, it is only necessary to remove the fastening devices employed to fasten the device to the `mast 20, then remove the retainer pin 37v from the head or casting and the bolt 66, after which the bolts 89 and 96 of the truss structure may be removed, permitting' the head orV casting to be separated from the other parts of the device and the two arms of the vreach or mast arm proper to be separated, and after removing the insulator arm from the casting by with-V drawing the bolt` 45 therefrom, all parts may be group-edv together in parallel arrangement so as to occupy comparatively littleV at its doubled-up end'being passed overthe T-shaped hook, as at 101. This wire 'is twisted in Vrear of'said hook and the two strands or stretches thereof are directed The wire there-V inwardly .and upwardly. fore has an eye at its front end, "which is hooked over the "T-shaped hook-99 and is prevented from becoming loosened reason of the lateral extensions 100^on `said* hook.

At `its inner end, each strand or stretch of this wire is doubled upon itself, as at 102, to form an outwardly-opening hook; 1t is thence recurved, as at108, to form an inwardly opening hook both hooks forming a substantially S-shaped yterminal on each strand or stretch of wire.

104 designates a Vsecuring fitting fastened to the Vmast by means of a bolt 105, said bolt being preferably passed through said mast and held in place by awasher 106 and a nut 107. This securing fitting, as best shown in Fig. 9, is in the form of Van elongated casting having two spacedside members 108 connected together attheir inner ends by a perforated dislror eye 109 through which said bolt-105%is passed, and said spaced side members are connected together attheir outer ends by a transverse portion 110 forming part of an upwardly and outwardly-directed eye 111. This fittingv there fore has an elongated opening 112, and acircular opening 113 formed in said `eye.n The inwardly openinghooks 103 formed at the extremities of the two strands or stretches of wire forming the overhead sup-port '(32fL are passed through the opening 112 between the side members 108 of said securing fitting and thence through the opening 113 in the eye 111, while the outwardly opening hooks -102 are passed through the opening 112 only. In this manner theinner ends of the two strands or stretches ofwire forming the overhead support are securely fastened to the securing fitting 104. I f desired, the inner ends of the overhead`support mayV be fastened to the mast in any other suitable manner.

that I have provided a' collapsible or knock-V down mast arm of simple construction, 'neat appearance'and few parts, and one which is comparativelylightin weight and capable of being stored or shipped in large vquantities while occupying minimum space.

It Aalso has the advantage of permitting its being assembled to readily change its appearance, since theA flanges ofthe Vreach `bars 24 may be rdirected. outwardly, the braceiar'm reversed, and the overhead support and brace arm used together, or either without the other. The insulatorA arm' may also be positioned in a forward or rearward position on the headl or casting and reversed in either position, or it may be hung from the head or casting in a forward position or'positioned underneath the head or casting inan upright manner, all of which will, to a certain extent, change the appearance of the mast arm andepermit the user to assemble the parts therof to suit his particular fancy. f Y

Whenrthe insulator arm is reversed, the insulators 49 are preferably provided at their outer ends with openings, suchf as shown lat 113, F ig. l5, to prevent rain loc ging therein and possibly creating a short circuit. l

It kwill further be apparent that long or short' reach or brace bars may be vemployed with the remaining parts of the structure, since mast arms of this kind vary in length, depending on the width of the road and other conditions. n Y Y Moreover, instead of using the mast arm in conjunction with an electric lamp, it may be employed as a support for overhead trolley wires, Vandv for various other purposes, and inV such instances the insulator arm may be changed in construction, or its use may be found unnecessary.

-Having thus described what I claimzj l. In combination with a mast, a mast arm including a reach having a hook at its upper side, an overhead support formed of wire detachably connected to said hook and extending upwardly and inwardly therefrom, said overhead support'having a hook at its inner end, a securing fitting having an opening therein through which the hook of said overhead support is passed, and means for securing said securing fitting to said mast. Y Y

In combination with a mast, a mast arm having a reach, anY overhead `support formed of wire and connected at one end to said reach and havingits other end Vdoubled upon itself and thence recurved to form a substantially S-shaped terminal, a securing fitting having two separated openings therein through one of which the doubled-up and recurved portion of said wire is passed and my invention,

through the other of which the recurved portion 'only of said wire is passed, and means for, securing said securing litting to said mast. i A mast Yarm comprising a reach having a headsecured to the outer end thereof, means on said head for connecting a lamp thereto, and an insulator arm connected to said head. l' Y 4. A mast arm comprising twoinwardlydiverging bars and a head connected to the outerends of said bars, a brace detachably connected to said head and extending inwardly and downwardly therefrom, an insulator arm detachably applied to said head, and means .on said head for kattaching a lamp thereto.

A mast-arm having a reach provided with a bolt hole and a tongue adjacent said bolt'hole at the top and bottom of said reach, an insulator arm provided with a groove at onel of its edges, said groove being adapted to receive the tongue at the top or the other tonguer at the bottom of said'inast arm under changed positions of said insulator arm on said mast arm, and a bolt eX- tending through said mast arm and insulator arm to fasten the latter to said mast arm.

'6. A mast arm having a bolt hole therethrough' and a pair of aligned tongues at the top and bottom in a plane intersecting said` bolt hole, an insulator arm having oblique end portions and a bolt hole and havingV also grooves in opposite edges arranged in pairs in planes to intersect the bolt hole in said insulator arm, said insulator arm being reversible and either pair of. grooves therein receiving the tongues at the top r bottom of said mast arm according to the connection of said insulator arm to said mast arm, and a bolt passing through said bolt holes and securing said insulator arm to said mast arm.

7. A mast arm having a boltV hole therethrough anda tongue at one side adjacent said bolt hole, a reversible insulator arm having a bolt hole and a groove at each edge thereof adjacent said last-mentioned bolt hole, eitherjof said grooves being adapted to receive said tongue, depending on the position of said insulator arm on said mast arm. Y

8. In combination with a mast, a mast arm having two inwardly-diverging bars, channel-shaped fasteners receiving the inner ends ofvsaid bars and having retainer prongs bent over the outer sides of said bars, and means passed through said bars and fasteners and adapted for connection to said mast. 9. A mast arm comprising a reach having inwardly-diverging bars, a bracel for said reach,said brace and bars being disposed in triangular relation, and a truss structure connecting said bars `and brace comprising a transverse rod disposed between said bars and having fittings at opposite ends lying against-said bars, and a rod disposedbetweeneach of' said bars and said brace and having fittings at opposite ends thereof, the fitting at one end of each of said lastmentioned rods (3o-operating with the fittings at opposite ends of said vtransverse rod and lying in contactwitli one of said bars,

Vand the fittings at the opposite ends there.-

of lying at opposite sides of said brace, and bolts passing through adjacent fittings to clamp the bars and brace therebetween.

lO.- AV Vmast arm comprising a reach having inwardly-diverging bars, la brace for lsaid reach, said-bars and brace being disposed in triangular relation, and a truss structure connecting-v said bars and brace and comprising three rods and disconnectable fittings at opposite ends of each of said rods, each of said bars and said'brace being reversibly retained between adjacent ittings, and bolts passed through adjacent tittings to securely fasten said bars and brace within said truss and tie them together.

ll. A mast arm comprising a reach having inwardly-diverging bars and a T-shaped brace detachably and reversibly connected to said reach, a truss structure connecting said bars and brace comprising a truss element disposed between said bars and a truss clement disposed between each of said bars and said brace, eachvvof said last-mentioned truss elements having a fitting at its lower end provided with spaced lugs adapted to receive one of the flanges of said brace therebetween when said brace is in either of its two positions, said fittings having two pairs of alined openings, one pairfbeing in a plane above said lugs and the other in a plane beneath the same, and a bolt passed through either pair of said bolt holes, depending on the position of said brace.

12. A mast arm comprising a reach. having two inwardly-diverging bars, a brace for said reach, said bars and brace being arranged in triangular relation, a trussstructure 'connecting said bars and brace and comprising a transverse rod having enlargements at opposite ends provided with upward and outward extensions, two downwardly-converging rods connected to said brace and having enlargements at their upper ends with upward and outward eXtensions, and bolts passed through the upward and outward extensions of the castings of said last-mentioned rods and the castings of said transverse rod for clamping said bars between said castings. v f

13. A mast yarm comprising ltwo inwardlydiverging bars and a head connected to the outer ends of said bars, a'brace detachably connected to said head and eXtendinginwardly and downwardly therefrom, an insulator arm, means provided in the construction oi' said head to permit the insulator arm to be detachably applied to the upper side of said head in different positions lengthwise thereof, or tok the under side of said head in reversed position, and means on said head for attaching a lamp thereto, l Y

In testimony whereof I aiiix my signature.

JOSEPH ,ISHICKLUNA v 

